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Bismuth vanadate single crystal particles modified with tungsten for efficient photoeletrochemical water oxidation
摘要： Highly efficient water oxidation utilizing visible light is a crucial step in water splitting. Bismuth vanadate (BiVO4) single crystal particles have attracted much attention in water oxidation recently, owing to their outstanding physicochemical properties and exposed active facets. The performance of BiVO4 single crystal particles is generally hindered by their poor conductivity and worse charge separation. Doping BiVO4 single crystal particles with other metal elements has been considered as an efficient way to improve their conductivity, charge separation and performance. However, there are few successful reports, because structure and morphology of BiVO4 single crystal particles are easily changed by addition of impurities. Here, we present that W doped BiVO4 crystal particles were successfully achieved by developing a simple impregnation method following with a high temperature annealing process. The obtained W-BiVO4 single crystal particles exhibited improved conductivity, carrier density and thereby enhanced activity for water oxidation. The solar energy conversion of the W-BiVO4 electrode was doubled compared with the pristine one. Thus, this work opens an avenue for developing efficient single crystal particle photocatalysts.
关键词： BiVO4,Tungsten,Single crystal particles,Water oxidation
更新于2025-11-19 16:51:07
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Surface decoration of BiOCl with BiVO<sub>4</sub> particles towards enhanced visible-light-driven photocatalytic performance
摘要： BiVO4/BiOCl p-n junctioned photocatalysts were synthesized by surface replacement of pre-synthesized BiOCl with BiVO4 via a hydrothermal route. BiVO4 particles were decorated on the surface of BiOCl, the structures of which were favored of maximizing absorption of visible light. The photocatalytic activity of the heterojunctioned composites were evaluated by degradation of Rhodamine B (RhB) dye under visible light illumination. The results indicated that the composites exhibited superior efficiencies for RhB photodegradation in comparison with pure BiOCl, BiVO4 and BiOCl/BiVO4 with similar compositions. The 30% BiVO4/BiOCl exhibited an optimal photocatalytic activity due to the combinative effects of large visible-light absorbance and carrier separation. Experiments on scavenging active intermediates demonstrated that the enhanced photoactivity was primarily attributed to the formation of p-n junction. An effective built-in electric field was formed by the interface between p-type BiOCl and n-type BiVO4, which promoted the efficient separation of photoinduced electron-hole pairs.
关键词： visible light absorption,BiVO4 decorated BiOCl,surface replacement,heterostructures,charge carrier separation
更新于2025-11-14 17:04:02
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Green Synthesis of Flower‐Like BiVO <sub/>4</sub> Nanoparticles by Solution Combustion Method Using Lemon ( <i>Citrus Limon</i> ) Juice as a Fuel: Photocatalytic and Electrochemical Study
摘要： BiVO4 have been proven to be one of the most promising photocatalyst for degradation of organic dyes and also exhibit good electrochemical performances in heavy metal detection. Herein, we have developed a simple, economic and low-cost combustion synthesis of BiVO4 nanoparticles using bismuth nitrate as an oxidiser, lemon (Citrus Limon) juice as fuel. The prepared nanoparticles were characterized by Powder X-ray diffractometer (PXRD), Fourier Transform-Infrared spectroscopy (FTIR), Diffused Reflectance Spectroscopy (DRS), Photoluminescence Spectroscopy (PL), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analytical techniques. Flower-like morphology BiVO4 nanoparticles were observed for higher ratio of fuel (Citrus Limon). BiVO4 nanoparticles showed an excellent photocatalytic activity towards degradation of Indigo Carmine dye in solution. Further, BiVO4 modified electrode was examined for the detection of Hg (II) using electrochemical techniques.
关键词： BiVO4,Nanoparticles,Electrochemical performance,Photocatalytic activity,Photoluminescence
更新于2025-09-23 15:23:52
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Facet effect on the photoelectrochemical performance of a WO3/BiVO4 heterojunction photoanode
摘要： Different WO3 facets have different surface energies and electronic structures, and exhibit different water oxidation abilities and photocatalytic performance as a result. Because of the material’s limited photoresponse region, loading a narrow bandgap material on WO3 is a generally known method for improving photo-harvesting. In this paper, we have synthesized WO3 films with different crystal facet ratios. After loading BiVO4 on these WO3 films, we measured the photoelectrochemical (PEC) performance to investigate the effects of WO3 facet choice on the heterojunction film electrode’s performance. We found that a high-intensity ratio of the (002) WO3 facet in X-ray diffraction (XRD) leads to a more negative onset potential and higher photocurrents in a lower potential region. The ultraviolet photoelectron spectra show a lower work function for the 002-dominant WO3 film compared to other WO3 films, which may result in a higher quasi-fermi level for the heterojunction electrode. Based on the XRD results, the high-intensity ratio of the (002) WO3 facet preferentially exposes the (020) BiVO4 facet, which may be a reason for the better charge extraction observed at low applied potential and high faradic efficiency on PEC water splitting. Together, this results in a high hole injection efficiency for 002-dominant WO3/BiVO4 films compared with WO3/BiVO4 films favoring other WO3 facet ratios.
关键词： BiVO4,WO3,Photoelectrochemical performance,Facet effect,Heterojunction
更新于2025-09-23 15:23:52
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Enhanced photocatalytic activity of hydrogenated BiVO4 with rich surface-oxygen-vacancies for remarkable degradation of tetracycline hydrochloride
摘要： In this work, for the first time the hydrogenation treatment was employed to introduce oxygen vacancies on the surface of BiVO4 (BVO) particles, and the influence of hydrogenation on the morphological structure and photocatalytic activity of BVO was explored. Compared to the pristine BVO, a disordered amorphous layer was observed on the surface of the hydrogenated BVO (HBVO) sample. The disordered layer was due to the formation of surface oxygen vacancies in HBVO, as verified by X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) spectra. Meanwhile, the band gap of HBVO was slightly narrowed accompanying with a higher optical absorption ability. The photocatalytic measurements demonstrated that under 30 min visible light (λ ≥ 420 nm) illumination the HBVO sample could photocatalytically degrade 98% of tetracycline hydrochloride (TCH), which was much higher than the pristine BVO (~52%), and the calculated pseudo-first-order degradation rate constant (k) of HBVO (~0.118 min?1) was about 5 times that of BVO, confirming that the hydrogenation treatment could significantly improve the photocatalytic activity of BVO. In addition, the photocatalytic mechanism of HBVO for enhanced photocatalytic TCH removal was also discussed. The present work demonstrates the feasibility of employing the hydrogenation treatment to develop highly efficient visible light BVO-based photocatalysts for photocatalytic removal of antibiotics, and also deepens the understanding of the correlation between surface oxygen vacancies and photocatalytic performance of semiconductor photocatalysts.
关键词： BiVO4,Photocatalytic activities,Tetracycline hydrochloride removal,Hydrogenation,Surface oxygen vacancies
更新于2025-09-23 15:23:52
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Effect of Mo doping and NiFe-LDH cocatalyst on PEC water oxidation efficiency
摘要： The NiFe-layered double hydroxide (LDH) nanosheets were decorated on the surface of doped BiVO4 to structure an integrating photoanode for improving solar photoelectrochemical (PEC) water splitting efficiency, which is a dynamic research topic to solve the energy crisis and remit environmental pollution caused by fossil fuel combustion. The fabricated photoanode exhibits rapid response to visible light, enhances photocurrent density and shows significant cathodic shift compared to BiVO4. Moreover, the measured incident photon-to-current efficiency (IPCE) of the photoanode is comparable to that reported in the literature. The amount of evolution oxygen was measured and the faradaic efficiency produced oxygen was also obtained by comparing the theoretical calculation value. The enhancement is attributed to the increase of the carrier density, the effective separation of photogenerated electron-hole and consuming of the photogenerated holes accumulated at the electrode surface, which has been confirmed by electrochemical impedance spectra (EIS) and the intensity modulated photocurrent spectra (IMPS). The work may offer a promising method for designing a high efficiency and low-cost photoanode.
关键词： NiFe-layered double hydroxides.,BiVO4,Mo-doping,Photoelectrochemical water splitting
更新于2025-09-23 15:23:52
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Simultaneous Cr(VI) removal and bisphenol A degradation in a solar-driven photocatalytic fuel cell with dopamine modified carbon felt cathode
摘要： In this work, a carbon felt cathode modified by dopamine (DPA/CF) was explored to enhance the cathodic reduction of Cr(VI) in a two chambers photoelectrochemical system, which was driven by solar light irradiation using BiVO4 photoanode. In the anode chamber, the bisphenol A (BPA) decomposition can be significantly improved by increasing pH to 8. The electron-hole pairs photogenerated on the surface of BiVO4 were efficiently separated by the application of the DPA/CF cathode. At the optimal conditions, 86% of low-concentration BPA was removed within 60 min. In the cathodic chamber, 80% of Cr(VI) was removed at pH of 4. Based on the XPS and electrochemical analyses, it was proposed that the positively-charged groups on the DPA/CF cathode led to the multilayer adsorption of Cr(VI) anions, which enhanced the reduction of Cr(VI) with the electrons generated on the BiVO4. On the other hand, the CeO groups on the DPA/CF electrode also played an important role as electron transfer mediator for Cr(VI) reduction. The prepared DPA/CF cathode associated with BiVO4 photoanode could be a potential application for efficient removal of Cr(VI) and organic pollutants under solar light irritation.
关键词： BiVO4 photoanode,Carbon felt cathode,Dopamine,Cr(VI),Solar photocatalysis,BPA
更新于2025-09-23 15:23:52
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Facile synthesis of hierarchically nanostructured bismuth vanadate: An efficient photocatalyst for degradation and detection of hexavalent chromium
摘要： Heterostructured nanomaterials can paid more significant attention in environmental safety for the detection and degradation/removal of hazardous toxic chemicals over a decay. Here, we report the preparation of hierarchically nanostructured shuriken like bismuth vanadate (BiVO4) as a bifunctional catalyst for photocatalytic degradation and electrochemical detection of highly toxic hexavalent chromium (Cr(VI)) using the green deep eutectic solvent reline, which allows morphology control in one of the less energy-intensive routes. The SEM results showed a good dispersion of BiVO4 catalyst and the HR-TEM revealed an average particle size of ca. 5–10 nm. As a result, the BiVO4 exhibited good photocatalytic activity under UV-light about 95% reduction of Cr(VI) to Cr(III) was observed in 160 min. The recyclability of BiVO4 catalyst exhibited an appreciable reusability and stability of the catalyst towards the photocatalytic reduction of Cr(VI). Also, the BiVO4-modified screen printed carbon electrode (BiVO4/SPCE) displayed an excellent electrochemical performance towards the electrochemical detection of Cr(VI). Besides, the BiVO4/SPCE demonstrated tremendous electrocatalytic activity, lower linear range (0.01–264.5 μM), detection limit (0.0035 μM) and good storage stability towards the detection of Cr(VI). Importantly, the BiVO4 modified electrode was also found to be a good recovery in water samples for practical applications.
关键词： Shuriken-shaped BiVO4,Durable bifunctional catalyst,Deep eutectic green solvents,Photocatalytic Cr(VI) reduction,Electrochemical sensing
更新于2025-09-23 15:23:52
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Synergistic Effect Between WO3/Activated Carbon and BiVO4 Nanoparticles for Improved Photocatalytic Hydrogen Evolution
摘要： Modified composite of the pure monoclinic tungstun oxide with 2.0% of activated carbon photocatalyst with BiVO4 as coupling content is synthezed via facile hydrothermal route. The composite is fabricated with coupling ratio of 0.5%,1.0%,1.5% and 2.0% dopant BiVO4. These composite were characterized by the XRD, SEM, UV–Vis, PL and BET to investigate the various properties (particle size, structural, morphological, purity and optical) and the energy band of the photocatalytic material. It is commonly examined that the C-WO3 showed the extraneous results for the evolution of the hydrogen energy by increasing the coupling contents upto 1.5% of BiVO4 and gave extraordinary photocatalytic activity towards the hydrogen energy production. The formation of the orthorhombic phases from the monoclinic and hexagonal at 2.0% of doping content indicated the increase of size of the particles and energy band gap. The average grain size of the composite is ranging from 30 to 50 nm. The increment of the BiVO4 content in the C-WO3 composite causes the reduction of photocatalytic activity because of the increase in the grain size and the forbidden gap of the photocatalytic composite.
关键词： BiVO4,WO3,Photocatalyst,H2 evolution
更新于2025-09-23 15:23:52
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A multiphase BiVO4 with the potential of being an environmental photocatalyst
摘要： Novel Y3+ and Mo6+ dual-doped, multiphased BiVO4 nanoparticles (NPs) were synthesised using a modified hydrothermal method through a gradient doping method. Yttrium (III) was used as a phase-stabilising agent for the tetragonal phase, while Mo6+ was used to control the volume of the crystals. The NPs were characterised using SEM, TEM, PL, FTIR, XRD, and BET to determine crystal phase, morphology, and surface area. It was found that the introduction of the dopants and formation of the phase junction lead to diminished PL spectra indicative of reduced electron–hole recombination. The 10% (m–m) Y–Mo dual-doped multiphased BiVO4 NPs have the highest electron–hole separation efficiency. However, 15% (m–m) Y–Mo had the least charge separation due to the formation of recombination centres at high degrees of metal doping. The multiphased systems also showed a red shift in the UV–Vis absorption spectrum. The Mott–Schottky plot obtained from electroimpedance spectroscopy confirmed the formation of a phase junction in the multiphased systems which resulted in an improvement of the photocurrent to twice that of the intrinsic BiVO4 NPs for the 10% Y–Mo BiVO4 NPs. The photocurrent for 10% Y–Mo was 0.025 A cm?2, while that of the intrinsic BiVO4 NPs was about 0.014 A cm?2. This increase in photocurrent proves the improvement of charge separation. BET results showed that surface area increased with an increase in the degree of doping and that the 10% Y–Mo dual-doped BiVO4 nanomaterials had a surface area of 9.009 m2/g. The 10% Y–Mo dual-doped BiVO4 reached 99.1% Cr6+ removal in 60 min.
关键词： Charge separation,Phase stabilisation,Multiphase BiVO4
更新于2025-09-23 15:23:52